(1) Field of the Invention
Much prior art exists that aims at reducing the vibrations of a bicycle and its rider caused by traversing over road irregularities. Mitigating vibrations induced by the road permits faster travelling speed and reduces material fatigue in addition to providing for rider comfort. This mitigation is hence fundamental to smart bicycle design.
On racing type road bicycles intended for use on smooth road surfaces where major pavement irregularities do not much exist, isolation from road vibrations is significantly provided for by gel or foam within the rider's clothing. These bicycles may also incorporate carbon fiber as a damping material in their front wheel forks and in all or part of their frames that also absorb road vibrations. Curved seat stays are sometimes incorporated into the bicycle frame to provide further vibration absorbing flexibility. The amount of road irregularity that may be absorbed by the means just described is limited to those of relatively high frequency and small amplitude. This limitation not withstanding as they are meant to be ridden on smooth roads, racing type road bicycles are fitted with light, small tube diameter, and hard highly pressurized tires for minimum rotating inertia and minimum rolling resistance to achieve high speed. Bicycles intended for somewhat more irregular than smooth road surfaces are often fitted with heavier, larger tube diameter, and softer less pressurized tires to absorb the greater road vibrations.
(2) Description of Related Art                Lund in U.S. Pat. No. 6,702,399 describes an open ended cylindrical shock absorber housing mounted concentrically within a wheel hub for absorbing road vibrations at the wheels.The ability to absorb vibrations of lower frequency and greater amplitude by these means about the wheels comes at the expense of greater rotating inertia and rolling resistance. Vehicle speed is compromised.        
Road vibration transmission to the rider is also addressed with various types of seat suspensions as exemplified:                Wang in U.S. Pat. No. 6,176,476 describes a suspension seat post.        Sinyard in U.S. Pat. No. 6,848,701 describes a bicycle seat post assembly having a cavity in which vibration dampening material is placed.        Allsop in U.S. Pat. No. 5,415,423 describes a bicycle seat suspended off a cantilever beam used a spring to provide the vibration isolating effect.These means effectively isolate the majority of the weight in travel which exists as the vehicle rider himself. The bicycle may be fitted with respective lighter, smaller tube diameter and harder higher pressure tires to achieve faster speeds. Vibration isolation at the seat post however does not provide isolation to the bicycle itself which resides below the seat post. The bicycle and also a portion of the rider through his legs are still subjected to the stress of road vibration. Also, quality seat posts that can effectively absorb low frequency higher amplitude vibrations can be complex in manufacture and costly to assemble.        
Suspension systems utilizing coiled springs and shock absorber components are incorporated into bicycles such as of the mountain bike type to accommodate the low frequency high amplitude deflections that are found in off road terrain:                Schmider in U.S. Pat. No. 7,104,562 describes a rear wheel suspension for a bicycle having a swing arm holding the rear wheel with a shock absorbing element connected between the swing arm and the frame.        Soucek in U.S. Pat. No. 7,066,481 describes a bicycle rear suspension with pivoting upper and lower links connected to both a front frame and a rear frame member with a shock absorber providing the vibration damping effect.        Chamberlin in U.S. Pat. No. 7,059,620 describes a bicycle frame assembly composed of a main frame and a sub frame with a shock absorber in between.These are examples of bicycle designs of the type incorporating what is commonly known as active suspension systems. Such active suspension systems dictate heavy and complex bicycle frame designs. Their use is usually intended for rough terrain where speed like of a road bike is not expected.        
Art exists that incorporates significant spring and dampening qualities into the bicycle frame itself:                Raco in U.S. Pat. No. 6,659,4877? Describes a flexible bike frame that uses a shock absorber as a frame member and a plurality of flexible joints throughout the remainder of the frame.        Castellano in U.S. Pat. No. 6,406,048 describes a pivotless rear suspension system for bicycles utilizing a planer truss chain stay member with a wide lateral side and a thin vertical side so as to be laterally rigid and vertically flexible in conjunction with a seat stay member composed with a shock absorber.        
Art also exists that moves away from the use of active shock absorber component by integrating spring and damping qualities directly into the passive members of the frame:                Kirk in U.S. Pat. No. 6,109,637 moves away from active shock absorber components by describing an elastomeric damper affixed to well curved seat stays for enhanced vibration absorption.        Schober in U.S. Design patent D520411 displays an ornamental bicycle suspension member that replaces the chain and seat of a common bicycle frame with a one piece formed chain and seat stay member that can be made of flexible plastic material.        Peraz in U.S. Pat. No. 6,932,371 describes a bicycle frame with a rear passive suspension configured to elastically deflect in the vertical direction while maintaining rigidity in other directions. The frame utilizes a pair of upper chain stays that control rear wheel motion while removing the seat stays found on common bicycles.        Buckland in U.S. Pat. No. 1,114,855 discloses a bicycle frame consisting of two pairs of parallel springs pivotally connected to opposite sides of the front steering head. He describes a set of spring strips starting at the bicycle's steering head that curves down to the axle of the rear wheel to which a seat post and pedals are attached.        Jenick in U.S. Pat. No. 2,264,981 discloses a bicycle having a frame substantially in the form of a parallelogram like that of a common road bike with members of the frame being metal spring strips held in place with spacersArt of this type appears for bicycles envisioned to absorb road vibrations greater than afforded by those of the road racing type albeit not as great as that of bicycles with active suspension systems designed for off road terrain. The vibrations desired to be absorbed appear of the frequency and amplitude encountered when traversing many city streets. The limitation that exist in this type of art comes from the materials of the frame members, but also from the frame member's length as dictated by common bicycle frame forms.        